Hopefully, nothing is wrong, but here's an article on Poo Patrol which states mucous in the stools is something that you may need to be concerned about and for $10.00 why not have it checked out? But I do agree with Oscar's Mom that I wouldn't be too stressed out about it either.
Taken from:
http://cyberpet.com/cyberdog/articles/health/poop.htm
Poop patrol helps you to monitor the health condition of your precious pet. As horrid as it might seem to analyze those feces, sudden changes in elimination habits could signal something physically wrong with your pet. In many cases, you can spot abnormalities quickly and take action to prevent more escalated veterinary problems or death. Having a good rapport with your veterinarian is important, so are regular check ups for your pet.
Litterbox avoidance, strange marking behavior, more frequent or less frequent toileting can be some of the signs you could see if something is wrong. There are many little things you could look for. By paying attention consistently, you will know what is normal and what is not. Telling the difference in abnormal consistency from too rich a diet and illness could be useful.
Blood or mucous in the stool could be something to follow up on by visiting the vet. Always check with your veterinary medical doctor if you suspect anything wrong. Seeing such things as white flecks in the stool may suggest tapeworms, have a fecal exam to rule out other worms too. If you have any sort of flea infestation they contribute to the problem, so get that under control too.
Remember, as a good pet owner your poop patrol duties include:
-keeping toileting areas clean for the health and welfare of your animals, family, and the other critters nearby
-cleaning up the public areas your pet soils
-being responsible enough to make sure your pet does not create a nuisance in the neighborhood by inappropriately eliminating or marking your neighbors property, and cleaning up after your critter if it does.
-monitoring the condition of your animal through paying attention while on poop patrol (remembering that any drastic changes in toileting habits may be a sign of something wrong)